[lint] Add lint and tests.

.dir-locals.el

@@ -0,0 +1 @@
+((python-mode . ((flycheck-flake8rc . "setup.cfg"))))

.flake8

@@ -1,2 +0,0 @@
-[flake8]
-max-line-length = 100

.gitignore

@@ -1,3 +1,13 @@
+# Editor files
 *~
-*.pyc
+
-**/__pycache__
+# Documentation build
+.tox
+doc/_build
+
+# Python files
+__pycache__
+.ipynb_checkpoints
+.mypy_cache
+**/*.egg-info
+**/.eggs

setup.cfg

@@ -0,0 +1,42 @@
+[flake8]
+# Use black line length:
+max-line-length = 88
+extend-ignore =
+    # See https://github.com/PyCQA/pycodestyle/issues/373
+    E203,
+
+[mypy]
+warn_return_any = True
+warn_unused_configs = True
+
+[mypy-pytest.*]
+ignore_missing_imports = True
+
+[mypy-IPython.*]
+ignore_missing_imports = True
+
+[tox]
+envlist = py35,py36,py37,py36-lint
+
+[gh-actions]
+python =
+    3.5: py35
+    3.6: py36, py36-lint
+    3.7: py37
+
+[testenv]
+deps =
+    pytest
+commands =
+    pytest tests
+
+[testenv:py36-lint]
+deps =
+    black
+    flake8
+    flake8-black
+    mypy
+commands =
+    black --check --diff setup.py simplex tests
+    flake8 simplex tests
+    mypy simplex tests

setup.py

@@ -2,23 +2,29 @@
 
 import setuptools
 
-with open('README.md', 'r') as fh:
+with open("README.md", "r") as fh:
     long_description = fh.read()
 
+install_requires = []
+test_requires = ["pytest", "mypy", "black", "flake8", "flake8-black"]
+
 setuptools.setup(
     name="simplex",  # Replace with your own username
     version="0.0.1",
-    author='Mikaël Capelle',
+    author="Mikaël Capelle",
-    author_email='capelle.mikael@gmail.com',
+    author_email="capelle.mikael@gmail.com",
-    description='Implementation of a simplex dictionary in python',
+    description="Implementation of a simplex dictionary in python",
     long_description=long_description,
     long_description_content_type="text/markdown",
-    url="https://github.com/mikael.capelle/simplex",
+    url="https://gitea.typename.fr/mikael.capelle/simplex",
     packages=setuptools.find_packages(),
+    install_requires=install_requires,
+    test_requires=test_requires,
+    extras_require={"test": test_requires},
     classifiers=[
         "Programming Language :: Python :: 3",
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
     ],
-    python_requires='>=3.5',
+    python_requires=">=3.5",
 )

simplex/magic_dictionary.py

@@ -1,29 +1,48 @@
 # -*- encoding: utf-8 -*-
 
+import typing
+
+V = typing.TypeVar("V")
+T = typing.TypeVar("T")
+
+
+class magic_dictionary(typing.Dict[V, T]):
 
-class magic_dictionary(dict):
     """
     A magic dictionary is a dictionary that:
       - May contain a default value, much like collections.defaultdict.
       - Raise custom errors when the given key does not match a given
         predicate.
       - Can convert values using a specific functor.
+
+    Magic dictionary can be constructed the same way standard python dictionary
+    are, except that the constructor takes three extra named parameters.
     """
 
-    def __init__(self, *args, key_predicate=None, value_converter=None, default_factory=None, **kwargs):
+    key_predicate: typing.Optional[typing.Callable[[V], typing.Optional[str]]] = None
-        """ Create a new magic dictionary from the given arguments. Magic dictionary can be constructed
+    value_converter: typing.Optional[typing.Callable[[typing.Any], T]] = None
-        in the same way as standard python dictionary, except that the constructor takes three extra
+    default_factory: typing.Optional[typing.Callable[[], T]] = None
-        parameters.
 
-        Parameters:
+    def __init__(
-        - key_predicate    Predicate to apply on new key, which should return None if the key is valid,
+        self,
-            or a message indicating why the key is invalid otherwize. The predicates is not applied on
+        *args,
-            the initial keys of the dictionary (from args or kwargs). Can be None.
+        key_predicate: typing.Callable[[V], typing.Optional[str]] = None,
-        - value_converter  Functor to apply to values in this dictionary, when set by the index operator.
+        value_converter: typing.Callable[[typing.Any], T] = None,
-            This functor is also applied to all initial values of the dictionary. Can be None.
+        default_factory: typing.Callable[[], T] = None,
-        - default_facotry  Default factory to use to create object when the key is not set. Can be None.
+        **kwargs
+    ):
+        """
+        Args:
+            key_predicate: Predicate to apply on new key, which should return None if
+                the key is valid, or a message indicating why the key is invalid
+                otherwize. The predicates is not applied on the initial keys of the
+                dictionary (from args or kwargs). Can be None.
+            value_converter:  Functor to apply to values in this dictionary, when set
+                by the index operator. This functor is also applied to all initial
+                values of the dictionary. Can be None.
+            default_facotry:  Default factory to use to create object when the key is
+                not set. Can be None.
         """
-
         super().__init__(*args, **kwargs)
 
         self.key_predicate = key_predicate
@@ -51,7 +70,7 @@ class magic_dictionary(dict):
             for k in self:
                 super().__setitem__(k, self.value_converter(self[k]))
 
-    def __getitem__(self, key):
+    def __getitem__(self, key: V) -> T:
 
         # If the key does not exists:
         if key not in self:
@@ -59,11 +78,10 @@ class magic_dictionary(dict):
             if self.default_factory is not None:
                 self.__setitem__(key, self.default_factory())
 
-
         # Return the key:
         return super().__getitem__(key)
 
-    def __setitem__(self, key, value):
+    def __setitem__(self, key: V, value: typing.Any):
         # If the key predicate is not empty, we check the key:
         if self.key_predicate is not None:
             check = self.key_predicate(key)
@@ -77,8 +95,12 @@ class magic_dictionary(dict):
         super().__setitem__(key, value)
 
     def update(self, *args, **kargs):
-        super().update(magic_dictionary(
+        super().update(
-            *args, **kargs,
+            magic_dictionary(
+                *args,
+                **kargs,
                 value_converter=self.value_converter,
                 key_predicate=self.key_predicate,
-            default_factory=self.default_factory))
+                default_factory=self.default_factory
+            )
+        )

simplex/simplex_dictionary.py

@@ -1,17 +1,27 @@
-from IPython.display import display, Math
+# -*- encoding: utf-8 -*-
+
+import typing
+
 from fractions import Fraction
 
 from .magic_dictionary import magic_dictionary
 
+# Type that can be converted by convert_value:
+convertable_type = typing.Union[str, int, Fraction]
 
-def convert_value(value):
+
+def convert_value(value: convertable_type) -> Fraction:
     if type(value) is float:
         # For float value, we don't handle float:
-        raise TypeError('Cannot set value as float, use fractions.Fraction instead.')
+        raise TypeError("Cannot set value as float, use fractions.Fraction instead.")
     return Fraction(value)
 
 
-class simplex_dictionary:
+# Type of variables in a simplex_dictionary:
+V = typing.TypeVar("V")
+
+
+class simplex_dictionary(typing.Generic[V]):
 
     """ Class representing a dictionary for the simplex algorithm. The class contains
     multiple members representing the elements of a dictionary.
@@ -28,13 +38,14 @@ class simplex_dictionary:
     The magic member ".variables" can also be used to access the list of all
     variables.
 
-    The various arrays of coefficients or values (b, a, c) are indexed by their respective
+    The various arrays of coefficients or values (b, a, c) are indexed by their
-    variables, which must be in B or N.
+    respective variables, which must be in B or N.
 
-    All values are converted to fractions.Fraction object in order to maintain consistency
+    All values are converted to fractions.Fraction object in order to maintain
-    in the dictionary.
+    consistency in the dictionary.
 
     Examples:
+    ```
     # Create a simplex dictionary with two basic and two non-basic variables:
     >>> sdict = simplex_dictionary(B=['x_1', 'x_2'], N=['x_3', 'x_4'])
 
@@ -43,114 +54,181 @@ class simplex_dictionary:
 
     # Set the coefficient of x_3 in x_1:
     >>> sdict.a['x_1']['x_3'] = 12
+    ```
     """
 
-    def __init__(self, B, N):
+    _a: magic_dictionary[V, magic_dictionary[V, Fraction]]
-        """ Create a new simplex dictionary with the given basic and non-basic variables.
+    _b: magic_dictionary[V, Fraction]
+    _c: magic_dictionary[V, Fraction]
+    _z: Fraction
 
-        Parameters:
+    def __init__(self, B: typing.Iterable[V], N: typing.Iterable[V]):
-          - B  The list of basic variables.
-          - N  The list of non-basic variables.
         """
-        self.__B = tuple(B)
+        Args:
-        self.__N = tuple(N)
+            B The list of basic variables.
-        self.b = {}
+            N The list of non-basic variables.
-        self.a = {}
+        """
-        self.c = {}
+        self.__B = list(B)
-        self.z = 0
+        self.__N = list(N)
+        self.b = {}  # type: ignore
+        self.a = {}  # type: ignore
+        self.c = {}  # type: ignore
+        self.z = Fraction(0)
 
-    def _check_basic(self, key):
+    def _check_basic(self, key: V) -> typing.Optional[str]:
         """ Check if the given key is a basic variable, returning None if it is,
         and a custom exception string if not. Suitable for magic_dictionary use. """
         if key not in self.B:
-            return '{} is not a basic variable.'.format(key)
+            return "{} is not a basic variable.".format(key)
         return None
 
-    def _check_non_basic(self, key):
+    def _check_non_basic(self, key: V) -> typing.Optional[str]:
         """ Check if the given key is a non-basic variable, returning None if it is,
         and a custom exception string if not. Suitable for magic_dictionary use. """
         if key not in self.N:
-            return '{} is not a non-basic variable.'.format(key)
+            return "{} is not a non-basic variable.".format(key)
         return None
 
     @property
-    def variables(self): return sorted(self.B + self.N)
+    def variables(self) -> typing.List[V]:
+        return sorted(self.B + self.N)
 
     @property
-    def B(self): return self.__B
+    def B(self) -> typing.List[V]:
+        return self.__B
 
     @property
-    def N(self): return self.__N
+    def N(self) -> typing.List[V]:
+        return self.__N
 
-    def __setattr__(self, key, value):
+    @property
+    def a(self) -> magic_dictionary[V, magic_dictionary[V, Fraction]]:
+        return self._a
 
-        # Base and non-basic:
+    @a.setter
-        if key == 'b':
+    def a(
-            value = magic_dictionary(
+        self,
-                value,
+        value: typing.Union[
-                key_predicate=self._check_basic,
+            typing.Mapping[V, typing.Mapping[V, convertable_type]],
-                value_converter=convert_value)
+            typing.Iterable[typing.Tuple[V, typing.Mapping[V, convertable_type]]],
-        elif key == 'c':
+        ],
-            value = magic_dictionary(
+    ):
-                value,
+        self._a = magic_dictionary(
-                key_predicate=self._check_non_basic,
-                value_converter=convert_value)
-        elif key == 'a':
-            value = magic_dictionary(
             value,
             key_predicate=self._check_basic,
             value_converter=lambda value: magic_dictionary(
-                    value, key_predicate=self._check_non_basic,
+                value,
-                    value_converter=convert_value),
-                default_factory=lambda: magic_dictionary(
                 key_predicate=self._check_non_basic,
-                    value_converter=convert_value))
+                value_converter=convert_value,
-        elif key == 'z':
+            ),
-            value = convert_value(value)
+            default_factory=lambda: magic_dictionary(
+                key_predicate=self._check_non_basic, value_converter=convert_value
+            ),
+        )
 
-        return super().__setattr__(key, value)
+    @property
+    def b(self) -> magic_dictionary[V, Fraction]:
+        return self._b
 
-    def name_latex(self, name):
+    @b.setter
-        """ Convert the given variable name. """
+    def b(
-        name = str(name)
+        self,
+        value: typing.Union[
+            typing.Mapping[V, convertable_type],
+            typing.Iterable[typing.Tuple[V, convertable_type]],
+        ],
+    ):
+        self._b = magic_dictionary(
+            value, key_predicate=self._check_basic, value_converter=convert_value
+        )
 
-        s = name.split('_')
+    @property
+    def c(self) -> magic_dictionary[V, Fraction]:
+        return self._c
+
+    @c.setter
+    def c(
+        self,
+        value: typing.Union[
+            typing.Mapping[V, convertable_type],
+            typing.Iterable[typing.Tuple[V, convertable_type]],
+        ],
+    ):
+        self._c = magic_dictionary(
+            value, key_predicate=self._check_non_basic, value_converter=convert_value
+        )
+
+    @property
+    def z(self) -> Fraction:
+        return self._z
+
+    @z.setter
+    def z(self, value: convertable_type):
+        self._z = convert_value(value)
+
+    def name_latex(self, name: typing.Any) -> str:
+        """ Convert the given variable name to a clean latex name.
+
+        Args:
+            name: The name of the variable to convert.
+
+        Returns:
+            A latex version of the given name.
+        """
+
+        sname = str(name)
+
+        s = sname.split("_")
 
         # We only handle special case:
         if len(s) == 1 or len(s) > 2:
-            return name
+            return sname
 
-        return s[0] + '_{' + s[1] + '}'
+        return s[0] + "_{" + s[1] + "}"
 
-    def value_latex(self, value):
+    def value_latex(self, value: Fraction) -> str:
+        """ Convert the given fraction to a latex fraction.
+
+        Args:
+            value: The fraction to convert.
+
+        Returns:
+            A valid latex code that is either a number (if the fraction has a
+            denominator of 1), or a latex fraction.
+        """
         if value.denominator == 1:
             return str(value)
-        return r'{}\frac{{{}}}{{{}}}'.format(
+        return r"{}\frac{{{}}}{{{}}}".format(
-            '-' if value.numerator < 0 else '',
+            "-" if value.numerator < 0 else "", abs(value.numerator), value.denominator
-            abs(value.numerator), value.denominator)
+        )
 
-    def display(self, name=None):
+    def display(self, name: str = None):
         """ Display this simplex dictionary on the standard Jupyter output.
 
-        Parameters:
+        Args:
-          - prefix  Name of the dictionary.
+            name: Name of the dictionary.
         """
-        d = (r'\begin{{array}}{{r||{}}}'.format(
+        from IPython.display import display, Math
-             'r|' * (1 + len(self.B)))
+
-             + r' & b & ' + ' & '.join(self.name_latex(v) for v in self.N) + r'\\\hline '
+        d = (
-             + r'\\'.join(
+            r"\begin{{array}}{{r||{}}}".format("r|" * (1 + len(self.B)))
-                    '{} & {} &'.format(
+            + r" & b & "
-                        self.name_latex(b),
+            + " & ".join(self.name_latex(v) for v in self.N)
-                        self.value_latex(self.b[b])
+            + r"\\\hline "
+            + r"\\".join(
+                "{} & {} &".format(self.name_latex(b), self.value_latex(self.b[b]))
+                + " & ".join(self.value_latex(-self.a[b][n]) for n in self.N)
+                for i, b in enumerate(self.B)
+            )
+            + r"\\\hline\hline "
+            + r"&".join(
+                ["z", self.value_latex(self.z)]
+                + [self.value_latex(self.c[n]) for n in self.N]
+            )
+            + r"\\\hline\end{array}"
         )
-                    + ' & '.join(self.value_latex(-self.a[b][n]) for n in self.N)
-                    for i, b in enumerate(self.B))
-             + r'\\\hline\hline '
-             + r'&'.join(['z', self.value_latex(self.z)] + [self.value_latex(self.c[n])
-                                                            for n in self.N])
-             + r'\\\hline\end{array}')
 
         if name is not None:
-            d = r'{} = \left.{}\right.'.format(name, d)
+            d = r"{} = \left.{}\right.".format(name, d)
 
         display(Math(d))

tests/test_magic_dictionary.py

@@ -0,0 +1,83 @@
+# -*- encoding: utf-8 -*-
+
+from simplex.magic_dictionary import magic_dictionary
+
+
+def test_basic():
+    """ Tests that a non-customized magic_dictionary acts
+    as a standard python dictionary. """
+
+    d = magic_dictionary()
+    assert len(d) == 0
+
+    d["x"] = 1
+    d["y"] = "2"
+
+    assert len(d) == 2
+    assert d["x"] == 1
+    assert d["y"] == "2"
+
+    # Test copy:
+    d2 = magic_dictionary(d)
+    assert len(d2) == 2
+    assert d2["x"] == 1
+    assert d2["y"] == "2"
+
+    # Test construction:
+    d2 = magic_dictionary({"x": 1, "y": "2"})
+    assert len(d2) == 2
+    assert d2["x"] == 1
+    assert d2["y"] == "2"
+
+    # Test construction:
+    d2 = magic_dictionary(x=1, y="2")
+    assert len(d2) == 2
+    assert d2["x"] == 1
+    assert d2["y"] == "2"
+
+    # Test construction:
+    d2 = magic_dictionary((("x", 1), ("y", "2")))
+    assert len(d2) == 2
+    assert d2["x"] == 1
+    assert d2["y"] == "2"
+
+
+def test_value_converter():
+    """ Tests that conversion is correctly done. """
+
+    # Convert a value to its string representation:
+    def converter(x):
+        return str(x)
+
+    d = magic_dictionary(value_converter=converter)
+    assert len(d) == 0
+
+    d["x"] = 2
+    d["y"] = 3
+    assert len(d) == 2
+    assert d["x"] == "2"
+    assert d["y"] == "3"
+
+    # Construction:
+    d = magic_dictionary(d, value_converter=converter)
+    assert len(d) == 2
+    assert d["x"] == "2"
+    assert d["y"] == "3"
+
+    # Construction:
+    d = magic_dictionary({"x": 2, "y": 3}, value_converter=converter)
+    assert len(d) == 2
+    assert d["x"] == "2"
+    assert d["y"] == "3"
+
+    # Construction:
+    d = magic_dictionary(x=2, y=3, value_converter=converter)
+    assert len(d) == 2
+    assert d["x"] == "2"
+    assert d["y"] == "3"
+
+    # Construction:
+    d = magic_dictionary([("x", 2), ("y", 3)], value_converter=converter)
+    assert len(d) == 2
+    assert d["x"] == "2"
+    assert d["y"] == "3"